The present invention relates to a breather device and an engine, particularly, to breather device provided in a 4-cycle engine which is configured to be mounted in a snow vehicle.
Generally, in a front part of a vehicle body of a snow vehicle, such as a snowmobile, an engine is mounted in an engine room covered with an engine mount frame, and as this engine, a 4-cycle engine prevails to meet the requirements, such as emission control and an improvement in fuel efficiency, against recent environmental problems.
It is necessary to provide this type of engine with a breather device as a means for releasing the pressure of blow-by gas within a crankcase to the outside and for separating atomized oil mixed into the blow-by gas from the gas.
As a breather device of a snow vehicle, on which the 4-cycle engine is mounted, for example, one (for example, refer to Patent Documents 1 or 2) in which a breather chamber is provided by creating a space in an upper part within a cylinder head cover of an engine and providing a partition plate in the space, one in which a breather tank is installed separately from an engine, and the breather tank is connected to the engine through a hose are suggested (For example, refer to Patent Document 3)
Patent Document 1: Japanese Utility Model Publication No. 63-7221 A
Patent Document 2: Japanese Patent Publication No. 2002-364468 A
Patent Document 3: Japanese Patent Publication No. 2002-339718A
However, in the breather device of an engine described in Patent the Patent Document 1 or 2, since the breather chamber is provided in an upper part within the cylinder head cover, the total height of the engine becomes high. Accordingly, the size of the engine becomes large.
On the other hand, in the breather device described in the Patent Document 3, the number of parts, such as the breather tank and the hose, is increased, and it is necessary to create an installation space for the breather tank and the hose. As a result, an engine hood becomes large. Further, the water in the breather tank might be frozen because the breather tank or the hose are cooled down by the wind during traveling.